1. Field of the Invention
The present invention relates to methods and apparatus for enhancing the production of hydrocarbons from a well, and in a particular, preferred context of use to methods and apparatus for producing low pressure gas wells containing water.
2. Description of the Prior Art
The usefulness of the present invention is probably best illustrated with reference to this preferred, non-limiting context of use. In this regard, gas producing formations often experience significant water encroachment as the gas is produced thereby reducing the gas formation pressure. The water builds up in the well bore penetrating the formation and eventually prevents the low pressure gas remaining from being produced. In order to return the gas formations containing low pressure gas and water to production, the water is artificially lifted to the surface thereby allowing the gas to be produced. The low formation pressure in most of the water-containing gas formations does not allow the use of artificial gas lift and plunger lift. The use of conventional rod pumping units is generally difficult due to the well depths and amounts of water that must be lifted. Mechanical and corrosion problems contribute to making the use of rod pumping units difficult.
A preferred form of artificial lift that has been used for low pressure water-containing gas wells utilizes an electrical submersible pump. A significant number of electrical submersible pumps are presently being used for producing low pressure gas wells containing water. However, due to the continuing decrease in water volumes in some of the gas fields utilizing electrical submersible pumps, the pumped water has fallen below the electrical submersible pump operating design. As a result, the electrical submersible pumps have often failed.
Thus, there are continuing needs for methods of reducing failures of electrical submersible water pumps in wells where the amounts of water produced by the wells have become substantially diminished.